fix: 允许文件未找到,设置allowEmpty：true

(cherry picked from commit 8894b5a8)

@@ -102,7 +102,7 @@ function copyFileUsageOssServer(cb) {
   const outPath = './build/oss'
 
   for (const filePath of copyFileList) {
-    src(path.resolve(__dirname, filePath))
+    src(path.resolve(__dirname, filePath), {allowEmpty:true})
       .pipe((dest(outPath)))
   }